You need to load a browser profile (with WebDriver) that doesn't have the setting for popup blocker enabled (using the Profile class and giving it the right properties). Then, you will get the Windows popup message concerning the SSL cert. If , for some reason, you cannot control the popup using WebDriver (because its limited to Action control only within the browser content window) then you can use Sikuli API to handle the dialog and export the cert to the "Downloads" dir and then copy the file to expected location for inspection. Unfortunately, if you use Sikuli, that will make your automation script sequential and not work via a RemoteWebDriver grid server and so you wont be able to run parallel tests. Hopfully, WebDriver gives you access to the dialog and so you will be able to run with RemoteWebDriver because that is the best way to go when running scripts, even if you run a browser locally.